Treatment of hydrocarbons



y 1938- H. v. ATWELL 2,118,288

TREATMENT OF HYDROCARB ONS Filed July 25, 1935 2 Sheefs-Shet 2 INVENTOR HAROLD l. ATWELL ATTORNEY Patented May 24, 1938 TREATMENT OF HYDROCARBONS Harold v. Atwell, White Plains, N. Y., assignor to Gasoline Products Company, Inc., Newark, N. J., a corporation oi- Delaware Application July 25, 1933, Serial No. 682,059

5 Claims.

My invention relates to the treatment of hydrocarbons, more particularly hydrocarbon oils and hydrocarbon gases containing unsaturated constituents such as olefins, and my inventionhas for objects the provision of a process of effecting inter-reaction between such hydrocarbon oils and gases and the recovery of valuable products therefrom, as well as such further improvements in operative advantages and results as may hereinafter be found to obtain.

With these objects in view, my invention contemplates contacting gaseous olefins or the like with normally liquid hydrocarbons containing un saturated, aromatic or naphthenic hydrocarbon constituents, such, for example, as so-called pressure tars and other residual oils produced in the pyrolytic decomposition of petroleum, petroleum oils or the like, the contact taking place. at elevated temperatures in the presence of limited quantities of oxygen or gases containing-same, withthe result that inter-reaction between the various hydrocarbons takes place resulting in the formation of valuable oils of intermediate boiling points compared to the hydrocarbons initially employed.

While the nature of the reaction or reactions taking place, due input to the complex nature of the hydrocarbon materials present, is obscure- Thus I may subject gaseous olefins or gases containing the same to contact at elevated temperature, preferably at a temperature within what may be designated as a range suitable for the cracking of hydrocarbon oil,'for example, from 750 to 1000 F., and under elevated pressure, with residual or other hydrocarbon oils f the character set forth, in the presence of /imited quantities of oxygen or gases containing .the same, the resultant products of reaction being removed and fractionated. as desired to recover normally liquid hydrocarbon products therefrom,

My invention further contemplates a method wherein hydrocarbon gases or oil may be cracked in such manner as to produce a mixture of hydrocarbons containing cracked constituents including unsaturated hydrocarbons, together with small quantities of oxygen, the mixtureof gases or vapors thus obtainedbeing brought into contact with hydrocarbon liquid containing reactive 5 hydrocarbon constituents at elevated pressure and temperature, and the products being'fractionated as desired.

In one aspect, my invention contemplates a process in which gases resulting from the combustion of a suitable fuel are reduced in temperature to a suitable point and brought into contact with hydrocarbon gas or oil to crack the same, the resultant mixture of gases or vapors, products of combustion and, it-may be, oxygen, being further reduced to a temperature of for example 1750" to 1000 F. and contacted at that temperature with residual-oil or tar, with or without the introduction of additional quantities of oxygen or oxygen-containing gases as desired, the products of reaction being fractionated as indicated hereinabove.

In order-that my invention may be clearly set forth and understood, I now describe, with refierence to the drawings accompanying and forming a part of this specification, a preferred manner in which my invention may be practiced and embodied. In these drawings,

vFigure 1 is amore or less diagrammatic view, partly in elevation and partly in verticalsection, of apparatus for treating hydrocarbons in accordance with my present invention; and

Figure 2 is a similar view of an alternative form of apparatus for carrying out my process.

Similar reference numerals designate similar parts in both views of the drawings.

Referring now to the drawings, there is shown an apparatus comprising in part a refractorylined furnace or combustion chamber l a refractory-lined cracking chamber 2, a reaction chamber 3, a dephlegmator 4, a fractionating tower 5, and a gas separator 6. The reaction chamber 3 may be empty or provided with gas-and-liquidcontact devices commonly used in the oil-cracking art.

A suitable fuel such as oil or gas is introduced .to aburner I located in the combustion chamber I through an inlet 8 having a pump 8a and valve 9; while air for combustion of the fuel is introduced to the burner 1 through a valved inlet Hi. The proportions of fuel and air may beadjusted to give substantially complete combustion or to provide an excess of air over that required for the combustion of the fuel. The products of combustion leave the combustion chamber l and 65 are passed through a refractory-lined duct 12 to the cracking chamber 2.

It is sometimes desirable to reduce the temperature of the products of combustion to about 1500 F. before entering the cracking chamber 2 and for this purpose I provide a valved inlet pipe l3 for steam or other diluent gas, and a valved inlet pipe I4 for air or oxygen, both of which pipes conveniently communicate with the duct l2, as shown. Any of these gases, or a mixture thereof, may be admitted to the products of combustion in such amount as to reduce. the temperature thereof to about 1500 F. Where air or oxygenis admitted at this point, the amount of the same admitted is such as to efiect combustion of any combustible constituents such as carbon monoxide, which may remain in the gases of combustion leaving the combustion chamber, and preferably also to provide a small amount of free oxygen in thegases entering the cracking chamber 2.

In the instance illustrated in Figure l, the gases entering the reaction chamber 2 through the duct l2 pass upward through an interiorly disposed duct I5 to the top of the reaction chamber 2 and then downward through a chamber I6, within which I may provide bodies I! of checkerbrick or other refractory and heat-accumulative material.

Hydrocarbon gas or oil of suitable character is introduced into the cranking chamber I6, to

chamber -l6 at a temperature of from 750 to 2500 F., the time of contact being so controlled as to effect material cracking of the hydrocarbon gas, resulting in the formation of unsaturated hydrocarbons, such as gaseous olefins or other reactive compounds. The products then pass through a conduit 2| into the reaction chamber 3.

At this point, additional quantities of air or other oxygen-containing gas or diluent gas may be introduced through a valved inlet 22 communieating with the conduit 2 I, while additional quantities of gaseous olefins or gases containing the same, such for example as gases produced in the cracking of hydrocarbon oils, may be introduced through a valved inlet 23 communicating with the reaction chamber 3.

Irrespective of whether excess oxygen beyond that required for combustion'of the fuel introduced at the burner l is introduced at In, at M,

or at .22, the process is preferably so conducted that the mixture of gases entering the reaction chamber 3 contains free oxygen. The introduction of air or oxygen-containing gas is so regulated as to provide a volume of oxygen less than that of the hydrocarbon gases or vapors present, and preferably equal to from 20 to 50 percent of the volume of the hydrocarbon gases and vapors.

in part by reaction with the hydrocarbon gases the addition of further quantities of oxygen at 22.

By means of a pipe 24, I introduce into the mixture of gases entering the upper portion of the reaction chamber 3 a suitable hydrocarbon liquid, preferably one containing a considerable amount of unsaturated, aromatic or naphthenic hydrocarbon constituents. Various heavy oils obtained in the pyrolytic decomposition of hydrocarbon oils, and preferably residual oils or tars high in reactive constituents, may be employed.

Through contact with the hot gases entering the reaction chamber 3, which gases contain such unsaturated hydrocarbons as gaseous olefins or the like together with. small quantities of free oxygen, constituents of the liquid introduced through the conduit 24 are caused to react with hydrocarbon gases within the reaction chamber 3 resulting in the formation of hydrocarbons of intermediate boiling points.

Preferably, thetemperature within the reaction chamber 3 is maintained within a range of from about 750 to about 1100 F. Where ,the temperature of the gases leaving the cracking chamber I6 is considerably above this range, cooling may be efiected by means of gas or liquid introduced through the inlets 22, 23 and 24, respectively, as will be readily understood by those skilled in the art.

While, as indicated hereinabove, I do not rely upon any particular theory as to the nature of the reaction taking place in the chamber 3, nevertheless it is probable that the oxygen present c-fiects a limited dehydrogenation of the hydrocarbon liquid or unsaturated constituents thereof, the resultant highly active products of reaction combining with gaseousolefins or otherwise polymerizing or reacting in the presence of the cracked hydrocarbons entering the reaction chamber 3 through the conduit 2! to form products of intermediate boiling points.

The reacting materials in the chamber 3 may be maintained under a substantially atmospheric pressure. Preferably, however, they are maintained under an elevated pressure, for example, from 50 to 200 pounds per square inch, or even higher if desired, and the same or higher pressures may be maintained in the chambers l and 2.

The gases and vapors reaching the bottom of the reaction vessel 3 are withdrawn therefrom through a conduit having a valve 3|, and may pass to the dephlegmator 4, or through a branch line 32 having a valve 33 directly to the fractionating tower 5. Ordinarily, however, I prefer to pass the gases and.vapors through the dephlegmator' 4 before admitting them to the-fractionating tower 5. The dephlegmator 4 is preferably provided with a plurality of baflles 35 and an inlet 36 for introducing a suitable reflux oil.

The liquid products of'reaction are withdrawn from the reaction vessel 3 through an outlet 31 having a valve 38, while liquid products from the dephlegmator 4 are withdrawn therefrom through an outlet 39 having a valve 40 and leading to a pump 4|. The former may be run to storage through a branch line 42 having a valve 43, or may be delivered to the pump 4| through a branch line 44 having a valve 45.

The heavy liquid products removed from the reaction vessel 3 and/or those removed from the dephlegmator 4, may be delivered in part or in .whole to the reaction vessel 3 through'a conduit 46, a branch line 41 having a valve 48 and the inlet 24, or to the burner 1 through a branch line 49, having a valve 5 9, andthe conduit 9. The partially dephlegmated vapors from the dephlegmator 4 and/or the vapors from the conduit 32 pass through a conduit 52 to the lower part of the iractionating tower 5, which is provided with a plurality oi plates or trays 53 of suitable design, as'well as an inlet 54 for admitting reflux oil. By means of coo in efiected by the addition of reflux to the tower 5 or otherwise,

the vapors passing up through the latter are fractionated, conditions being preferably so regulated as to recover a traction of the nature of a gas oil which collects in the bottom of the tower 5, i'rom which it is withdrawn by means of a conduit 55 having a valve 56 and leading to a pump 51.

A portion of this gas-oilfraction may be withdrawn through the line 35, wherein is located a valve 53, and delivered to the dephlegmator 4.

This portion of the gas-oil fraction may be cooled.

if desired, before introducing it into the dephlegmator 4.

The gases and uncondensed vapors withdrawn from the top of the tower 5 pass through a vapor line 99 to a condenser 5|, and thence through a line .62 .tothe gas separator 9. Condensate, comprising a low boiling'hydrocarbon liquid of the naphtha or gasoline type, is withdrawn from the o separator 9 through a-conduit 53 having a valve 54. A portion of the condensate maybe returned as ,reflux to the tower 5 through the line 54,

which is provided with a valve 55 and a pump 99 for this purpose.

Uncondensed gases are removed from the separator 5 through a conduit 51 having a'valve 63,

and may be disposed of as desired. .Due to the relatively high proportion of incondensable gases passing through the system, it may often be desirable to scrub the gases from the separator 5 with a suitable solvent, for the recovery 01' vainable light-constituents therefrom. andtor this purpose I provide a scrubber I9 having an inlet .Hand an outlet 12 for a suitablesolvent, such 5 as cool gas oil or other-hydrocarbon oil. The

. scrubbed gases, consisting almost entirely of fixed gases and gaseous products 01 combustion, escape from the scrubber 19 through an outlet I3 and may bedisposed of as desired. The enriched oil 1 withdrawn through the outlet 12 may be treated in any suitable manner for the recovery oflabsorbed constituents therefrom. I

In 1-"igu.re 1 I have also illustrated apparatus for employing excess heat generated within the combustion chamber' hior the purpose of effecting a preliminary distillation or cracking of oil.

for example a crude petroleum or a reduced crude, whereby such oil ,may. be treated for the recovery of various constituents thereof, one or no more of such constituents being employed in those portions of the apparatus describedhereinabove.

Thus, in Figure 1, Ihave illustrated pipe coils 99, and 32 located within ,the combustion chamber I in, such manner as tobe heated by 55 the combustion of fuel introduced in the burner.

l. The location of the coils, 3l and 92 within I the combustion chamber l is preferably such" that the coil 99 is subjected to the highest heat,

coil 92 to the. lowest heat, whilecoil'9l is subjected to an intermediate degree ofheat.

when heavy oil or tar is to be introduced from an outside source-into the reaction chamber 3,

it may first be delivered by a pump 93 through a conduit 94to the coil 92, where it is heated to a 7 temperature short of a cracking temperature, for

mater 93.

. 3 example, from 400? to 609 F., or even to a cracking temperature of, for example, from about 750 .to 1000 F. The resultant heated products are then discharged through conduits and 95 and the inlet 24 to the reaction chamber 3. v

I The coils 99 and 9| may also be used for a similar purpose and in the specific instance illustrated in Figure 1 are employed tor thecracking o! a suitable oil such, as, gas oil, for example, gas

oil recovered in the fractionating tower 5. .Such.

gas oil may be delivered to thecoils 9| and 99 by means of-the pump 51 and atconduit 99, while additional gas oil may also be supplied to the coils Bi and 99 through a conduit 9|. In this instance, I provide a reaction vessel 92, a primary dephlegmator 93 and a fractionation tower 94,

, Fresh oil, for example, a crude petroleum or a reduced crude is introduced-to the system by means of a pump 95 through a conduit '95 to pass through a heat-exchange coil 91 located in the upper portion of the fractionating tower- 94,

mator 93, and a combined dephlegmating anddistilling action takesplace. Res idual portions of the charge oil, together with condensed portions of the vapors entering the dephlegmator, 93, are

, withdrawn from the bottom of the dephlegmator 93 through a conduit I92 having a valve I93, to be discharged through the conduit 99 and an inlet 24 into'the reaction chamber 3., However, a portion or all of the liquid collecting in the bottom of the dephlegmator 93 may .be withdrawn through a branch conduit I94 having a valve I95 and a pump I99, by means of which this oil may be delivered to the reaction vessel 92. Vapors reaching the top of thedephlegmator 93 pass through a conduit. l9! to the bottom of the fractiona-ting tower 94, the interior of which is prov videdwith'suitable plates or trays I99, and-in which, due to the cooling eifect of the oil passing through the heat-exchange coil 9I,'a'dephlegmating and fractionating action takes place,

This action is so regulated as to permit the recovery atthe base of the i'ractionating tower 9.4 oi a stock suitable-for cracking, for example gas oil, which isthen delivered througha valve H9 and a pump III to the conduit 9! to be supplied to the coils 3t and 99. Inthe latter theses ena heated to a cracking temperature of, for exampleirom 750 to 10 50 F. under a. suitable pressureof, for example, from 59 to 1900 pounds persquare' inch. The hot cracked-products from the coil 39 pass through a transfer line H3 to the reaction vessel 92 wherevthey, mayJbe joined by liquid-removed from the base of the dephleg- In the reaction vessel 92 a partial separation into vapors and liquid occurs, the vapors 'passingthrough the conduit i9l into the dephlegmator 93 as stated hereinabove, while the liquid is withdrawn through a conduit H5 having a valve 9 to be deliveredthroughthe conduit 95 .onthe inlet "to thereaction vessel 3;

The vapors and gases remaining uncondensed at thetop of the fractionating tower 94 pass through the vaporline 129 to a-condenser l 2l and thence througha conduit I22 to a gas separator 123, from which liquid condensate comprising naphtha or gasoline may be removed I under higher pressure.

through a pipe I2 3 having a valve I25. Gases leave the separator I23 through a conduit I26 having a valve I27 and 'may either be taken ofi through a branch conduit I28 having a valve I29 or may be permitted to flow through the conduit I25 and the inlet 23 to the vessel 3.

Whenthese gases are insufficient or unsuitable for the purpose in view, additional gas may be introduced from an outside source through a conduit I32 having a valve I 33 and provided with a pump or fan I36 and leading to the inlets It and IQ. Various gases may be employed for this purpose, such, for example, as methane, ethane, propane, butane, ethylene, proplyene and other hydrocarbon gases or mixtures of these, such as natural gas and refinery gas.

In general, of course, it is desired to introduce gases'containing considerable amounts of unsaturates to the vessel 3; such gas may be obtained from the separator I23, especially when the cracking effected in the coil 80 and chamber 92 is'of the high temperature vapor phase type, or gas from an outside source may be employed as indicated. i

It will be obvious that, while I have illustrated coils 80, 8i and 82 located within the combustion chamber I, these heating coils may be located in a separate furnace if'so desired, especially where it is'desired to maintain the combustion chamber Moreover, when the coils 80, M and 82 are located within the combustion chamber I, it may be desirable to provide more heat at this point than is required for the cracking and reaction taking place in the vessels 2 and 3. For the purpose of removing part of the gases of combustion leaving the combustion chamber I, the vessel 2 is provided with a stack I08 having a valve MI, whereby a suitable portion of the gases reaching the top of the vessel permitted to pass through the chamber IS an 2 may be bled on to the atmosphere without being the subsequent apparatus.

In Figure 2, I have illustrated a modified form of apparatus which is especially suitable for use when very high pressures and temperatures are to be employed. As shown in this figure, the apparatus comprises a metal shell I 5d of more or less cylindrical shape, the interior of which is divided by means of a refractory liner I 5i into a combustion chamber I52,-a cracking chamber or passageway I53, and a reaction chamber I 56.

Fuel and air are admitted to a burner I55 located in the combustion chamber I 52 through valved inlets I 56 and I5I,-respectively, the combustion being controlled to produce gases of combustion having a limited amount of free oxygen.

As the gases of combustion pass from the combustion chamber I52 into the passageway I 53, they are brought into direct contact with a suitable hydrocarbon gas or oil introduced through an inlet pipe I58 having a valve I59. A pyrolysis or cracking of the hydrocarbon gas or oil takes place, resulting in the formation of unsaturated.

hydrocarbons, mainly of a normally gaseous character, for example, gaseous oleiins and the manner set forth hereinabove, the introduction of oil or tar being preferably insuiiicient amount to reduce the temperature of the cracked gases and vapors from a passageway I53 to, for example, from 800 to 1000 F. The resultant vapors and residiual liquid maybe separately withdrawn through valved outlets IE t and'IGS, respectively, or may be withdrawn together through a valved outlet I66. In the former instance, the gases and vapors withdrawn through the conduit I66 are fractionated in the usual 7 manner while the liquid withdrawn through the outlet I65 may be flashed or otherwise treated to recover valuable constituents therefrom, while in the second instance the combined gases, vapors and liquids drawn through the outlet I66 may be delivered to a separating chamber before being fractionated in the usual manner.

In this instance, pressure of from 50 to 200 pounds or even higher maybe maintained within the shell I50 and the temperatures in the combustion chamber may vary from around 1000" F.

substituted 'for that portion of the apparatus I embodied within the scope of the claims here- 'inafter made.

shown in Figure 1 which is intended to perform the same functions, and any of the various expedients illustrated in Figure 1 may be employed in conjunction with the apparatus illustrated in Figure 2. For example, the residual liquid withdrawn from the reaction vessel I54 may be eniployed as a fuel or may be recycled to the inlet I58.

Furthermore, while I have illustrated in Figure 1 a specific form of oil-cracking apparatus,

it will be obvious that this apparatus may vary considerably in character, and that my invention may be employed in conjunction with many types of cracking apparatus for producing the oils or tars and gases 'to be used in my process.

It will therefore be apparent to those skilled in the art that my invention is not limited to the specific examples given hereinabove' by way of illustration, but may variously be practiced and I claim: 7

- 1. The process of effecting thermal conversion of hydrocarbons which comprises passing a hydrocarbon oil through a cracking zone and there subjecting it to an elevated temperature effective like. The mixture of cracked gases and vapors' through an inlet pipe ISI having a valve I62. Within the reaction chamber I56, which is preferably provided with a bafle It8,the cracked gases 1;. and hydrocarbon oils are caused to react in the ,tar containing substantial quantities of reactive constituents, this oil or tar being introduced to crack said oil, separating vaporous'and residual conversionproducts, fractionating the vapors to separate a gasoline fraction, 2. higher-boiling fraction and uncondensed gases, contacting said drocarbon oil through a cracking zone and there subjecting it to an elevated temperature effective to crack said oil, separating vaporous and residual conversion products, fractionating the vapors .to separate normally liquid constituents from uncondensed gases, contacting said gases with said residual conversion products at a temperature of from 750 to 1100 F. in the presence of a limited amount of free oxygen, fractionating resultant vaporous products of reaction to recover normally liquid products therefrom including materials having boiling points above a gasoline boiling point range, and delivering at least a portion of the thereby recovered normally liquid products having boiling points above a gasoline boiling-point range to said cracking zone for further conversion.

3. The process of effecting thermal conversion of hydrocarbons which comprises subjecting a hydrocarbon oil to an elevated temperature effective to crack said oil, separating vaporous and residual conversion products, fractionating the vapors to separate normally liquid constituents from uncondensed gases, cracking said gases at a temperature in excess of 1300 F. to form gaseous olefins, contacting resultant cracked olefinic gases with said residual conversion products at a temperature of from 750 to 1100 F. in the presence of a limited amount of free oxygen, andiractionating the resultant products of reaction to recover normally liquid products therefrom.

4. The process of effecting thermal conversion of hydrocarbons which comprises passing a hydrocarbon oil to a cracking zone and there subjecting it to an elevated temperature eiiective to crack said oil, separating the vaporous and residual conversion products, fractionating the vapors to separate a gasoline fraction, a higherboiling fraction and uncondensed gases, contacting said gases with cracked residual hydrocarbon oil at a temperature of from 750 to 1100 F. in the presence of'a. limited amount of free oxygen, fractionating resultant vaporous products of reaction to recover another gasoline fraction and another higher-boiling fraction, and delivering at I least a portion of said other higher-boiling fraction to said cracking zone for further conversion.

5. The process of effecting thermal conversion of hydrocarbons which comprises passing a hydrocarbon oil'through a cracking zone and there subjecting it to an elevated temperature eflective to crack said oil, separating vaporous and residual conversion products, fractionally condensing the vapors to recover gasoline therefrom contacting said residual conversion products with unsaturated hydrocarbon gases at a temperature of from 750to 1100 F. in the presence of a limited amount of free oxygen, fractionating resultant vaporous products of reaction to re- ,cover another gasoline fraction and another higher-boiling fraction and delivering at least a portion of said other higher-boiling fraction to said cracking zone for further conversion.

I IAROLD v. ATWELL. 

